There's a chance, albeit small, that this watermark was added by someone besides 20th Century Fox — by someone trying to hide the identity of the actual source, maybe.

More likely, the watermark is accurate and Ellen's screener simply ended up in the wrong hands. A postal worker, one of her employees, friend, family member, or countless others in the production and distribution chain could be responsible for ripping the DVD and putting it online.

Indeed, one of those possibilities is the most likely answer, as it's extremely doubtful that Degeneres herself suddenly decided to make a bit of a name for herself in the warez scene. Either way, I'm sure that 20th Century Fox and/or the MPAA enforcement division of the local FBI can now more easily track down the history of how this all got online. I'm sure that large sums of money will be spent tracking it down... without anyone stopping to think that the fact that this is online is unlikely to make even the slightest difference in the eventual revenue for the film, which currently has a 48% approval rating on RottenTomatoes. The film was going to leak online sooner or later no matter what. Does it really matter where it came from?